The invention relates to a music tone generating system which can generate a music tone related to a key which is depressed to key in entry data exceeding the maximum digits a display device can display while the display device is displaying the entry data previously keyed in within the maximum digits.
In some of the recent electronic calculators, part or all of the key switches are related to music tones such as C, D, E . . . and when a key switch is depressed, the music tone related to the depressed key switch is generated. Accordingly, an operator may identify the key depressed auditorily. Further, if keys are operated in succession properly, a simple song can be played.
In operating this type of electronic calculator which can execute a calculation, generate a music tone and play a song by operating the same key or keys, an operator selects a mode from a plurality modes. A calm mode associated with an operation mode is selected when the operator desires to generate no sound at the time of the key operation. Inversely, when the operator desires to generate sounds in such a case, a sounding mode is selected. In operating keys, if the operator desires to play a music piece, a music playing mode is selected. In the second mode, or the sounding mode, for example, when the entry keys within the number of digits proper to the display section of the electronic device are depressed, the entry data keyed in by the depressed keys are displayed by the display section while at the same time the music tones are generated for each digit or key. However, when a key is depressed keying in entry data corresponding to the digit exceeding to the display digits of the display section, no display of the entry data is performed and no music tone related to the depressed key is generated.
In the third mode or the music playing mode, no entry data is displayed in the display section; however, in this mode, the generation of the music tones corresponding to the display digits of the display section and the music tones corresponding to the entry data of the digits exceeding the display digits may be generated by operating the related keys, regardless of the number of display digits in the display section, and further a music piece may also be played similarly.
The selection of one of those three modes is made by means of a slide switch, generally. The structure of the slide switch is complicated when it is used as a part of the electronic switch. A push button is sometimes used for the mode selection switch, instead of a slide switch. In this case, the number of keys used for the electronic device increases or a double function key with a multifunction must additionally be used. Further, an amount of program to be microprogrammed into the ROM (read only memory) increases with more complicated design of an electronic circuit including an ROM.
Accordingly, an object of the invention is to provide a music tone generating system in which the entry data are displayed by operating the entry keys corresponding to the display digits of the display section while at the same time the music tones corresponding to the display digits are generated, and when an entry key corresponding to a digit exceeding the display digits of the display section is operated, the music tone corresponding to the digit exceeding the display digits is generated while the display of the entry data in the display section is maintained.